Transmission for dobby looms



arch '29, 1955 c. o. JANSEN 2,705,023

TRANSMISSION FOR DOBBY LOOMS Filed Nov. 23, 1953 2 Sheets-Sheet l 49 24 Fly. 4. 6 7 8 20 Q 4 1a nfi 27 I ;7IIIIIII INVENTOR. Car/ 0/'/'0 Ja sen 5 29, 1955 c. o. JANSEN 2,705,023

TRANSMISSION FOR DOBBY LOOMS Filed Nov. 23, 1953. 2 Sheets-Sheet 2 BY M /RM United States Patent TRANSMISSION FOR DOBBY LOOMS Carl Otto Jansen, Dulken (Rhld.), Germany Application November 23, 1953, Serial No. 393,913 Claims priority, application Germany November 25, 1952 6 Claims. (Cl. 139-76) The present invention relates to dobby looms and, more particularly, to drives for dobby looms. The heretofore known gear dobby looms having two oppositely running driving drums, which are partly provided with teeth, and comprising lifter wheels arranged between said drums and tiltably supported by levers (the so called Knowles dobby motion) have the great disadvantage that they cannot run backwards due to their particular way of operation. However, with many fabrics, especially with double plush, a backward movement of the loom is indispensable in order to be able to weave out faulty portions. Therefore, it has heretofore been necessary in such instances. when employing the above mentioned known dobby looms, to provide the loom with complicated reversing mechanisms which, in order to allow weaving backwards, cause the dobby card, the pick counter, and the pile control of the loom to run backwards whereas the loom itself with the dobby runs forwards. The proper manipulation of this auxiliary de vice and the searching for the proper card requires considerable skill as well as the full attention of the operator and thus represents a considerable loss in time.

it is, therefore, an object of the present invention to provide dobby looms with a drive which will overcome the above mentioned drawbacks.

It is another object of this invention to provide a dobby loom which will allow running the dobby in the same manner as an ordinary eccentric loom, i. e. without having to switch back and forth and without searching for cards.

Still another object of this invention consists in the provision of a drive for dobby looms and also for use in connection with the shuttle changing, which may selectively be caused to run forwards or backwards.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings in which:

Fig. l is a diagrammatic total view of an arrangement according to the present invention.

Fig. 2 illustrates some details of the ratchet wheel or locking mechanism shown on a somewhat smaller scale in Fig. 1.

Fig. 3 represents of Fig. 2.

Fig. 4 illustrates a section through a coupling latch for use in connection with the present invention.

Fig. 5 illustrates a top view of a portion of a transmission for dobby looms according to the invention.

General arrangement The primary feature of the present invention consists in that the lifter wheels provided with teeth and carrying the lifter elements such as crank or eccentric are rotatably mounted and are driven by means of gears which are in continuous mesh with said lifter wheels. The arrangement is such that said gears are rotatably supported by a shaft driven intermittently in such a manner that said shaft stops between each two successive complete revolutions. According to the invention, the said gears may selectively be connected with said shaft for rotation therewith or may be held stationary with regard to said shaft so that the lifter wheels and consequently the elements actuated thereby during the respective working cycle may either carry out a movement or be held stationary in conformity with the desired a section taken along the line III-Ill requirements. The connection of the gears with said shaft for rotation thereby may according to an advantageous embodiment of the invention be effected by spring-urged coupling latches respectively arranged in grooves or transverse bores of the main shaft and movable outwardly so as to engage corresponding grooves in the bore of said gears. In order to interrupt the driving engagement between said shaft and any of said gears, the respective coupling latch is during the periodic or intermittent stop of said shaft withdrawn from the respective gear and, by means of a control lever controlled by the respective pattern card, pressed into said shaft to such an extent that said latch cannot engage any longer the groove in the respective gear. Simultaneously a pawl connected to said control lever engages a tooth space of the respective gear and arrests the latter so as to prevent rotation thereof.

Structural arrangement Referring now to the drawing in detail, it may be stated that for sake of clarity Fig. 1 shows the arrangement according to the present invention only in connection with one shaft lifting lever 1, one lifter wheel 7 and one gear 10. However, the dobby loom is according to the present invention provided with a plurality of the arrangement illustrated in Fig. 1 as shown in Fig. 5. With this understanding, a plurality of shaft lifting levers 1 are tiltably mounted on a stationarily supported shaft 2 and are arranged one behind the other. These levers 1 are in a manner known per se by cords or chain drives 26 and through the intervention of rollers 27 or levers connected with the heald shafts 3 likewise arranged one behind the other.

Each individual shaft lifting lever 1 is moved back and forth by a connecting rod 4 having one end thereof pivotally connected to the pivot 5 carried by the lever 1, whereas the other end of the connecting rod 4 is pivotally connected to a pivot 6 carried by the lifter wheel 7 provided with teeth 7a. The lifter wheels 7 are arranged one behind the other and supported by short studs 8 carried by respective sheet metal brackets 9. These lifter wheels are so supported by said studs 8 that each wheel 7 can be rotated individually and independently of the other wheels so that each shaft lifting lever 1 can correspondingly be actuated independently.

Each of the lifter wheels 7 has its teeth 70 in continuous mesh with one of the gears 10 which, as stated above are likewise arranged one behind the other and are supported by the main shaft 11. The diameter of the gears 10 equals half the diameter of the lifter Wheel 7 and the teeth of gear 10 equal half the number of the teeth 7a so that one complete rotation of the gear 10 causes the lifter wheel 7 to complete half a revolution.

The main shaft 11 is intermittently driven by the loom so that the shaft 11 with each complete cycle of the loom will carry out a complete revolution and will then stop for a period which according to the requirements has a certain ratio to the time required for a complete revolution of said shaft 11. The means for carrying out such intermittent movement are well-known in the art and therefore are not shown in the drawing. The direction of rotation of the shaft 11 is irrelevant and, if desired the shaft 11 instead of turning always in the same direction may alternately turn in one direction and then in the other direction.

The gears 10 are mounted on the shaft 11 in such a manner that selectively they may be held stationary with regard to said shaft 11 or be rotated by the latter. To this end, the gears 10 are provided with groove-like recesses 12 adapted to be engaged by spring-urged locking latches which are arranged in radially extending recesses provided in the main shaft 11 and spaced from each other in conformity with the arrangement of the gears 10. This coupling latch arrangement is shown on a larger scale in Fig. 2. As wil be seen from Fig. 2, the main shaft 11 is at those portions thereof which support the gears 10 provided with deep radially extending grooves 13. Slidably mounted in each of said grooves 13 is a coupling latch 14 adapted to engage the recess 12 of the respective gear 10 pertaining thereto. The coupling latch shown by itself in Fig. 4 and shown in Fig. 3 in a position turned by about its longitudinal axis, comprises a prismatic steel body of an appropriate size which is provided with a bore open toward the bottom of the groove 13 while being closed toward the recess 12 in the gear 10. Mounted in said bore 15 1s a pressure coil spring 16 having one end thereof resting on the bottom of the groove 13 while the other end presses against the closed end of the bore 15. The coupling latch 14 is furthermore provided with two protruding cars 17 which from the closed end of the bore 15 extend outwardly and laterally of the gear 10 so as to straddle the same. The central portion 24 of latch 14 which is located between the ears 17 is adapted due to the thrust of the spring 16 to engage the recess 12 of gear 10 to thereby establish a coupling engagement between the shaft 11 and the gear 10 for rotating the latter in response to the rotation of said main shaft 11. The position occupied by the shaft 11 as shown in Figs. 1 and 2 represents the basic position or rest position, i. e. the position which the shaft occupies during its intermittent stop. In this position, the recess 12 of each gear 10 registers with each groove 13 of the main shaft 11. As will be clear from Fig. 1, in this position the lifter wheels 7 together with their crank pins 6 occupy one dead center point position.

The arrangement according to the present invention furthermore comprises a relatively wide pawl 18 adapted to engage that tooth space of the gear 10 which is aligned with the recess 12. The pawl 18 is connected in any desired manner to a control lever which is rotatably mounted on a shaft 19 which latter is preferably stationary. Each of the gears 10 has associated therewith such a control lever 20. Each of the control levers 20 is engaged by one end of a traction spring 21 the other end of which is stationarily held so that the spring 21 continuously urges the lever 20 to withdraw the pawl 18 from the gear 10.

The arrangement according to the invention furthermore comprises a pattern wheel 23 with a composite roller card or pattern chain 25. The roller card is provided with a riser or lifting element 22 which in conformity with the showing of Fig. 2 has the shape of a roller and is adapted to engage a curved surface 20a of the control lever 20. Therefore, as will be clear from Fig. 2 the control lever 20 and thus the pawl 18 are always pulled away from and held in spaced relationship to the gear 10 by the spring 21 unless a lifting element 22 is in engagement with the lever surface 20a and presses the pawl 18 into the respective tooth space of the gear 10.

In order to enable the pawl 18 to press the coupling latch out of the recess 12, the width of the pawl 18 (see Fig. 3) is such that the pawl 18 protrudes on both sides of the gear 10 so that, when the pawl 18 engages the respective tooth space of gear 10, it will contact the two ears 17 of the coupling latch 14 and by means of said ears will press the latch 14 completely out of the recess 12 into the groove 13. It is, of course, obvious that to this end the length of said cars 17 must be such that, when the pawl has fully entered the respective tooth space of gear 10, the central portion 24 forming a part of the coupling latch 14 and located between the ears 17 does not extend any longer into the recess 12 of the gear 10.

Operation The arrangement according to the present invention operates in the following manner: during the intermittent stop of the main shaft 11, the pattern wheel 23 is each time rotated by one link. A lifting element 22 engages the surface 20a of the control lever 20 and thus presses the pawl 18 into the respective tooth space of the gear 10 so that the latter removes the coupling latch 14 from the recess 12 and presses said latch into the main shaft 11. Thus, the respective gear 10 will not be rotated by the main shaft 11 and will simultaneously be prevented by pawl 18 from any accidental rotation.

If during the movement of the respective roller card 25 no lifting element 22 engages the surface 20a of the respective adjacent control lever 20, the pawl 18 pertaining to said control lever 20 remains outside the respective tooth space of the gear 10 so that the respective coupling latch 14 engages the adjacent recess 12 of gear 10. In this instance the said gear 10 must rotate together with the main shaft 11 when the latter turns so that the lifter wheel 7 meshing with said last mentioned gear 10 will perform half a revolution thereby correspondingly adjusting the heald shaft 3.

It will thus be clear from the above, that a lifting element 22 in the roller card 25 whenever engaging the adjacent control lever 20 will bring about a stop of the heald shaft 3, whereas when such lifting element 22 is missing, i. e. the lever 20 is not engaged by a lifting element 22, a movement of the heald shaft 3 is effected. Thus, the roller card is to be composed in such a manner that a lifting element is to be inserted only in correspondence to the desired stops of the heald shaft between the individual wefts of the weave design.

In contrast to the heretofore customary gear dobby looms with which the lifter wheels for actuating the shaft lifting levers are turned forwards and backwards by the lifter wheels 7 according to the present invention always move in one direction from one dead center to another dead center. The direction of rotation in this instance is immaterial so that also the main shaft 11 of the machine with the gears 10 can be driven in either direction without jamming or the danger that the machine will break. The pattern wheel 23 which during the stand-still of the main shaft 10 is each time indexed or advanced by one step or notch, is connected with the machine drive through the intervention of a transmission so that it will follow, i. e. move in the same direction as the machine or loom. In other words the roller card or a pattern chain 25 will likewise move backwards when the loom moves backwards so that the lifting elements which during the forward movement caused the respective heald shaft to stand still will during the backward movement likewise bring about a standstill, whereas when a lifting element is missing, during the forward movement a movement of the heald shaft was effected which movement will during the backward motion be effected precisely in opposite direction. It will, therefore, be obvious that in order to undo the fabric or in order to effect a backward weaving it is merely necessary to cause the entire loom with the machine to run backwards, without the necessity of a special searching for cards.

It is, of course, understood that the present invention is, by no means, limited to the particular construction shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. In a dobby having reciprocable heald shaft means and a drive shaft adapted to convey actuating power to said heald shaft means and operable intermittently so as to stop between each two successive complete revolutions, the combination of: rotatable lifter gear means, lever means operatively connected to said rotatable lifter gear means and said heald shaft means for selectively actuating the latter, rotatable driving gear means supported by said drive shaft and in continuous driving connection with said lifter gear means, and coupling means operable selectively to effect or interrupt driving connection between said drive shaft and said driving gear means to thereby selectively efli'ect or interrupt the transfer of actuating power from said driving shaft to said lever means.

2. In a drive for use in connection with a dobby having a plurality of heald shafts arranged one behind the other and having a drive shaft operable intermittently so as to stop between each two successive revolutions, the combination of: a plurality of lifter members provided with teeth respectively drivingly connected with said heald shafts for actuating the same, a plurality of driving gears arranged one behind the other on said drive shaft and respectively arranged in continuous driving connection with said lifter members, a plurality of coupling means supported by said drive shaft and respectively associated with said driving gears, each of said coupling means being operable independently of the other coupling means for selectively effecting or interrupting driving connection between the respective driving gear pertaining thereto and said drive shaft.

3. In a drive for use in connection with a dobby having a plurality of heald shafts arranged one behind the other and having a drive shaft operable intermittently so as to stop between each two successive revolutions, the combination of: a plurality of lifter members provided with teeth respectively drivingly connected with said heald shafts for actuating the same, a plurality of driving gears arranged one behind the other on said drive shaft and respectively arranged in continuous driving connection with said lifter members, a plurality of coupling means arranged in and protruding from said drive shaft and normally effecting coupling connection between said drive shaft and said driving gears respectively, a plurality of lever means respectively arranged near said coupling means and operable selectively for actuating said coupling means so as to make the same ineffective, said lever means being operable independently from each other, yielding means normally holding said lever means spaced from said coupling means, pattern wheel means respectively arranged near said lever means, and means carried by said cylinder means and operable to actuate the respective adjacent lever means to cause the latter to make the respective coupling means ineffective.

4. In a drive for use in connection with a dobby, having a plurality of heald shafts arranged one behind the other and having a drive shaft operable intermittently so as to stop between each two successive revolutions, the combination of: a plurality of lifter gear means, respectively drivingly connected with said heald shafts for actu ating the same, a plurality of driving gears mounted one behind the other on said drive shaft and respectively arranged in continuous driving connection with said lifter gear means, said drive shaft being provided with a plurality of spaced radially extending bores corresponding in number to the number of said driving gears and in alignment therewith, each of said driving gears being provided with a recess movable into alignment with the adjacent radial bore in said shaft, spring-urged latch means reciprocably mounted in said radial bores and movable into the respective recess of the adjacent driving gear when said recess is in alignment with the adjacent radial bore for effecting a coupling engagement between said drive shaft and the respective driving gear, and a plurality of means respectively arranged adjacent each driving gear and operable selectively to engage the respective latch means to interrupt said coupling engagement.

5. In a drive for use in connection with a dobby, having a plurality of heald shafts arranged one behind the other and having a drive shaft operable intermittently so as to stop between each two successive revolutions, the combination of: a plurality of lifter gear means, respectively drivingly connected with said heald shafts for actuating the same, a plurality of driving gears mounted one behind the other on said drive shaft and respectively arranged in continuous driving connection with said lifter gear means, said drive shaft being provided with a plurality of spaced radially extending bores corresponding in number to the number of said driving gears and in alignment therewith, each of said driving gears being provided with a recess movable into alignment with the adjacent radial bore in said shaft, spring-urged latch means reciprocably mounted in said radial bores and movable into the respective recess of the adjacent driving gear when said recess is in alignment with the adjacent radial bore for effecting a coupling engagement between said drive shaft and the respective driving gear, a plurality of lever means including pawl means respectively arranged for cooperation with said driving gears, each of said lever means being pivotally supported and operable so as selectively to cause said pawl means to engage that tooth space of the adjacent driving gear which is in alignment with the recess in said respective driving gear, yielding means normally holding said pawl means out of engagement with the respective driving gears, roller card means, rotatable supporting means respectively arranged near said lever means for supporting said roller card means, and means supported by said roller card means and operable during an intermittent stop of said drive shaft to actuate said lever means to thereby cause said pawl means fully to move said latch means out of the recess of the adjacent driving gear while simultaneously holding the latter in its respective position.

6. An arrangement according to claim 5, in which said latch means is provided with two spaced ears straddling the respective driving gear, and in which said pawl means has a width wider than the distance between said ears.

References Cited in the file of this patent UNITED STATES PATENTS 421,608 Pollard Feb. 18, 1890 1,371,564 Leeming Mar. 15, 1921 FOREIGN PATENTS 453,928 Germany Dec. 22, 1927 

